Stable free radical containing contrast media

Abstract

The present invention relates to a method of generating a magnetic resonance image of a sample comprising introducing into the sample a physiologically tolerable deuterated stable free radical, exposing the sample to first and second radiations of frequencies selected respectively to excite nuclear spin transitions in selected nuclei in the sample and to excite electron spin resonance transitions of the free radical coupled to nuclear spin transitions of at least some of the nuclei, detecting free induction decay signals from the sample, and generating a magnetic resonance image from these signals.

I claim: 
     
       1. A method of generating a magnetic resonance image of a sample, said method comprising introducing into said sample a physiologically tolerable deuterated stable free radical having an electron spin resonance transition having a linewidth of 1 Gauss or less, exposing said sample to first and second radiations of frequencies selected respectively to excite nuclear spin transitions in selected nuclei in said sample and to excite electron spin resonance transitions of said free radical coupled to nuclear spin transitions of at least some of said nuclei, detecting magnetic resonance signals from said sample, and generating a magnetic resonance image from said signals. 
     
     
       2. A method as claimed in claim 1 wherein said deuterated radical is administered into said sample at a concentration from 0.1 to 1000 mM. 
     
     
       3. A method as claimed in claim 1 wherein magnetic resonance imaging is carried out at a primary field strength of 5×10 -5  to 0.1 Tesla.